A frame-based DQDB protocol for consecutive slots transmission in Gbit/s metropolitan area networks

A frame-based distributed-queue dual-bus (FB-DQDB) medium access protocol is proposed for Gb/s networks. By dividing the slots into fixed-size frames and delaying a channel access until the beginning of the next frame, each station can transmit a number of consecutive slots up to the limit of a frame size. It therefore reduces the packet reassembly processing overhead and the number of receiving buffers required. By allowing each station to make multiple requests on the request channel and with one request per frame, the FB-DQDB protocol can give a maximum throughput and fair bandwidth allocation among the stations over a wide range of cable lengths. It gives a throughput close to 1 with fixed-size messages and its throughput is lower with variable-size messages